This invention concerns removal of hydrocarbon components from a contaminated water stream. More specifically the invention relates to a system which uses oxidation/reduction, changes of vapor pressure and atomization of the liquid stream to separate and outgas difficult-to-remove components that typically are liquids at standard temperature and pressure.
Abatement of hydrocarbon contamination in soils and ground water is increasingly mandated in the United States, Canada and other countries. In California and several other states of the U.S., the addition to gasoline of MTBE has been required, supposedly to increase the efficiency of gasoline combustion in internal combustion engines, so as to release less pollutant to the air. However, this has turned out to be a serious mistake of monumental proportion, since the toxic MTBE has rapidly found its way into soils, ground water, lakes and streams. Moreover, once in soils, the MTBE produces a toxic organic byproduct, TBA (tributyl acryl). TBA in water such as ground water is extremely difficult to remove, and no efficient method or system has been found prior to the present invention.
U.S. Pat. No. 5,767,060, owned by the assignee of the present invention, discloses a multi-component medium through which contaminated water can be filtered to remove many noxious hydrocarbon components. The system is efficient at removing nearly all hydrocarbon components, including MTBE, but not TBA.
U.S. Pat. Nos. 4,979,886, 5,424,045 and 5,863,510 are concerned with remediation of contaminated water and soil which may contain combustible hydrocarbons. The first patent discloses separation of hydrocarbons from water by spray aeration of a heated water stream under vacuum. The first and second patents both describe combustion of the recovered hydrocarbon vapors in internal combustion engines.
It is an objective of this invention to remove TBA, MTBE and other hydrocarbon contaminants including BTEX from a contaminated water stream using an efficient process embodied in a compact and portable apparatus, to extract these contaminants down to a level below 0.2 parts per billion as is now required in some jurisdictions.